Sensing elements that are exposed to high temperatures and vibration loads, such as those that can occur, for example, within the exhaust system of motor vehicles, are known. The electrical supply leads to such sensing elements are exposed to considerable temperature stresses, that conventional cable insulation cannot withstand. In particular, the connecting points of the sensing elements to the electrical supply leads, and their insulating layers, must be effectively shielded against excessive temperatures. In lambda probes, for example, heat-resistant metal-sheathed lines, which must have a certain minimum length are usually used. Only beyond a specific distance from the heat-stressed measurement location can conventional cables take over the electrical connection to a downstream analysis unit.
The connecting point between the heat-resistant metal-sheathed line and the conventional cable line must, however, be configured so as to be completely sealed against external influences. Also any excessive length of the metal-sheathed line is problematic, and creates the risk of vibration breakage. The metal-sheathed line must therefore be as short as possible because of the vibration loads that occur, so that the requirements for the connecting point comprise not only sealing against environmental influences and moisture, but also the greatest possible temperature resistance.
Connections between a rigid metal-sheathed line and flexible cable lines that are injection-coated with plastic. Since, however, it is generally not possible with an injection-coated plastic sheath of this kind to create sealed connections between the metal-sheathed line and the insulated cable lines, additional measures, for example elastomer seals, are necessary. The volume of the connection and its mass and thus the moment of inertia increase as a result of these measures. This has a disadvantageous effect on the vibration resistance of the sheathed lines, thus subjecting them to a risk of breakage.